Plasma and serum are two words that often get thrown around in medical jargon, but what is the difference between them? Are they the same thing or entirely different entities altogether? If you’ve ever found yourself scratching your head over these terms, don’t worry – you’re not alone. In this blog post, we’ll demystify plasma and serum by uncovering their differences and shedding light on how they’re collected and used. Whether you’re a healthcare professional or just curious about these biological fluids, read on to learn everything you need to know!


Plasma is a yellowish fluid component of blood that makes up approximately 55% of the total volume. It consists of water, electrolytes, plasma proteins, hormones, and carbon dioxide. Plasma plays a crucial role in maintaining blood pressure and transporting nutrients throughout the body.

One important function of plasma is to transport antibodies that help fight infections. These antibodies are produced by white blood cells known as B-lymphocytes and are carried by plasma to various parts of the body where they can neutralize pathogens such as bacteria or viruses.

Read also: What is the Difference Between TD & TC Pipettes?

Another vital role played by plasma is in clotting. When an injury occurs, platelets in the bloodstream clump together at the site to form a plug that stops bleeding. This process requires several factors found in plasma, including fibrinogen and prothrombin.

Plasma donation involves extracting this fluid from healthy donors so it can be used for transfusions or other medical procedures. The process usually takes around 45 minutes and involves removing whole blood from one arm using a sterile needle while returning the red blood cells back into your other arm.

Understanding what plasma is and how it functions within our bodies is essential to appreciate its importance as both an indicator for disease states and a valuable therapeutic tool for patients with specific conditions.


Serum is a crucial component of our blood, just like plasma. However, unlike plasma that’s full of clotting factors, serum lacks them. Serum refers to the clear liquid leftover after blood clots form and red and white blood cells have been removed.

The process for collecting serum starts similarly to plasma collection – by drawing whole blood from a patient or donor through a needle into a vacuum tube. The difference between the two collection methods lies in the next steps taken with the sample.

After drawing whole blood, it’s allowed to clot naturally before being centrifuged at high speeds. This separates the solid particles from the liquid portion of the sample, allowing us to collect pure serum.

Serum has several diagnostic uses in medical settings since it contains proteins and other molecules that aid in identifying various diseases or conditions. It can also be used for research purposes and even cosmetic treatments due to its regenerative properties.

All in all, while similar to plasma in some ways, knowing what sets them apart is essential when it comes down to their respective applications.

The Difference between Plasma and Serum

Plasma and serum are two essential components of blood, each with their own unique properties. While they may seem interchangeable, there are significant differences between the two.

Plasma is a yellowish fluid that makes up about 55% of blood volume. It contains water, proteins (such as albumin and globulin), glucose, ions (such as sodium and potassium), hormones, clotting factors and waste products. Plasma’s role is to transport these substances throughout the body to various tissues.

Serum on the other hand is similar to plasma in composition but lacks some of its key components such as clotting factors due to the removal process necessary for collection purposes. Serum also has higher levels of certain enzymes compared to plasma since it doesn’t contain anticoagulants like heparin or EDTA which can alter enzyme activity.

The main difference between plasma serum lies in how they’re collected from blood samples. Plasma is obtained by separating cells from whole blood using an anticoagulant while serum results from allowing a clotted sample without any anticoagulation treatment.

Both plasma and serum have different uses in medical testing; measuring different things based on their distinct compositions – thus making them critical components when diagnosing diseases or disorders within patients’ bodies .

How is Plasma Collected?

Plasma is a crucial component of blood that carries various nutrients, hormones, and proteins throughout the body. So how do we collect plasma from donors?

The process of collecting plasma is known as plasmapheresis and involves drawing a donor’s blood through an intravenous line into a sterile machine called a plasmapheresis device. This machine separates the plasma from other components of the blood like red and white blood cells.

Once separated, the remaining cellular components are returned to the donor’s bloodstream while only plasma is collected. The entire process usually takes around 60-90 minutes.

Another method for collecting plasma is through whole-blood donations followed by centrifugation to separate out the plasma portion. However, this method yields less usable plasma compared to plasmapheresis.

After collection, donated plasma undergoes rigorous testing for infectious diseases before being processed into life-saving therapies such as immunoglobulins or clotting factors used to treat conditions like hemophilia or immune deficiencies.

Donating plasma can be a meaningful way to help others in need while also earning compensation for your time and effort.

How is Serum Collected?

Serum collection is a critical process that involves drawing blood from the patient’s vein. Serum is obtained after the blood has been allowed to clot and then centrifuged, separating it from the red and white blood cells. The resulting clear fluid is serum.

Before collecting serum, healthcare providers first verify that patients have fasted for at least 12 hours to minimize interference with test results caused by food digestion. They also ensure that they are not taking any medications or supplements that may affect their test results.

The process of drawing blood for serum collection begins with sanitizing the skin overlying where the needle will be inserted into a vein using alcohol or chlorhexidine solution. A tourniquet may also be used to enlarge veins before inserting needles.

After obtaining enough sample volume, healthcare professionals carefully remove the needle and apply gauze pressure on top of it while instructing patients to keep holding onto it for several minutes. This helps prevent bleeding and bruising complications.

Serum collection requires careful attention to detail in order to obtain an accurate diagnosis from laboratory testing. It can provide valuable insights into medical conditions ranging from infections, liver function abnormalities, electrolyte imbalances as well as many others.

Uses for Plasma and Serum

Plasma and serum are both vital components in various medical procedures, and their uses differ depending on the situation. Plasma is mostly used for transfusions to increase blood volume or replenish clotting factors. Additionally, plasma also contains antibodies that can help fight against viral infections like hepatitis B or C.

Serum, on the other hand, is commonly used in diagnostic tests as it does not contain any of the clotting factors found in plasma. It is an excellent source of biomarkers which can provide valuable information about a patient’s health status. For example, elevated levels of certain enzymes like creatinine kinase may indicate muscle damage.

Another use for serum is therapeutic drug monitoring (TDM), wherein concentrations of drugs in a patient’s bloodstream are measured to ensure they remain within safe and effective ranges. TDM helps healthcare providers adjust medication dosages accordingly to avoid potential side effects or toxicity.

While plasma and serum share some similarities in their composition, their unique properties allow them different applications within the medical field. Their importance cannot be overstated when it comes to lifesaving treatments such as transfusions or helping diagnose various diseases accurately.


We have uncovered the differences between plasma and serum. While both of these components are vital to medical research and treatments, they each have their unique characteristics that make them valuable for specific purposes.

Plasma is the liquid portion of blood that contains clotting factors, while serum does not contain those factors since it’s obtained after blood coagulation. Plasma is collected using an anticoagulant tube, while serum requires a clot activator tube or a plain red top tube to avoid contamination.

Read also: What Is A Buffer & How Does It Work?

Both plasma and serum have many uses in medicine such as diagnosing diseases like HIV/AIDS or measuring levels of certain metabolites or proteins important for human health. Researchers can use either component to develop new drugs or therapies.

Understanding the differences between plasma and serum is crucial in various fields like pharmacology, biochemistry, immunology, hematology among others. With this knowledge at hand you’ll be better prepared next time you hear about one of these two words!

Leave a Reply

Your email address will not be published. Required fields are marked *